package net.curisit.securis;

import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;

import net.curisit.securis.beans.RequestBean;
import net.curisit.securis.utils.JsonUtils;
import net.curisit.securis.utils.LicUtils;

import org.apache.commons.io.IOUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class LicenseValidator {

	private static final Logger LOG = LogManager.getLogger(LicenseValidator.class);

	private static LicenseValidator singleton = new LicenseValidator();
	protected static byte[] LOGO_SECRET;

	static {
		try {
			LOGO_SECRET = "Logo ipsum s3cr3t test áíóú".getBytes("utf-8");
		} catch (UnsupportedEncodingException e) {
			LOG.error("Unexpected error getting LOGO secret", e);
		}
	}

	private LicenseValidator() {
	}

	public static LicenseValidator getInstance() {
		return singleton;
	}

	/**
	 * @return CRC string for customer logo
	 */
	public String getCrcLogo() {
		InputStream is = getClass().getClassLoader().getResourceAsStream("images/logo_customer.png");
		try {
			String shaLogo = LicUtils.sha256(IOUtils.toByteArray(is), LOGO_SECRET);
			return shaLogo;
		} catch (IOException e) {
			LOG.warn("Customer logo was not found in images/logo_customer.png");
			return null;
		}
	}

	public void validateLogo(RequestBean reqBean) throws SeCurisException {
		if (reqBean.getCrcLogo() == null) {
			LOG.info("Customer logo is not included in license file and won't be validated");
		} else {
			String currentCRC = getCrcLogo();
			if (!currentCRC.equals(reqBean.getCrcLogo()))
				throw new SeCurisException("License logo validation failed for request data: " + JsonUtils.toJSON(reqBean));
		}
	}

	public void validateHW(RequestBean reqBean, String appCode, String customerCode) throws SeCurisException {
		RequestBean currentHW = ReqGenerator.getInstance().createRequest(appCode, customerCode);
		if (!currentHW.match(reqBean)) {
			throw new SeCurisException("Current System info mismatch the License System info:\n Licensed: " + JsonUtils.toJSON(reqBean, true) + "\n Expected: " + JsonUtils.toJSON(currentHW, true));
		}
	}

}